The Sirens were beautiful but dangerous creatures that lured the sailors with their beautiful voices to their doom, causing the ships to crash on the reefs near their island. They were the daughters of the river god Achelous, while their mother may have been Terpsichore, Melpomene, Sterope or Chthon. Although closely linked to marine environments, they were not considered sea deities. The texts mentioning the Sirens provide different opinions as to their number and their names; some mention two or three; others mention more.

The Sirens were probably considered the companions of Persephone, daughter of goddess Demeter. The latter had given them wings in order to protect her daughter; however, after Persephone's abduction from Hades, Demeter cursed them. The Sirens' song was a beautiful, yet sad melody, eternally calling for Persephone's return.

The Argonauts encountered the Sirens but successfully evaded them; Orpheus, who was on board, started playing his lyre so beautifully that the music completely drowned the Sirens' song. Another well-known encounter is that described in the Odyssey; Odysseus, advised by Circe, plugged the crew's ears with wax and ordered them to bind him on the mast of the ship. He also told them that no matter how much he begged, they should not untie him. When they passed near the Sirens' island, Odysseus started begging his shipmates to let him go, but none heard him; instead, they tied him even more. After they passed, Odysseus let them know that they were now in safe waters.